Grow room question filter

A question from a fellow grower:

i have room 30 ft x10x8
8 lights 1000w 8 inch opening
2 rows by 4 lights
for cooling what is best option with filter?
i was thinking out 780 cmf fan at front and same fan at end of lights install v from 2 ducts to 1 and use filter with 1 ducting going outside
do u think that is good idea?

By yourroom specs; I come to 2400CF. So a 780 cfm fan would refresh the air in 3+ minutes. I am not sure I would be satisfied with that in such a large grow room. I would probably opt for a fan on each line.